Abstract

Thomas Polger and Lawrence Shapiro (or P&S) have recently (2008) criticized ?causal-mechanist? views of realization that dominate research in the philosophy of mind and metaphysics of science. P&S offer the internal criticism that any account of realization focusing upon property instances, as views of causal-mechanist realization routinely do, must lead to incoherence about multiple realization. P&S's argument highlights important issues about property instances that have recently been neglected, as well as raising a challenge to the standard approach to understanding the non-causal relations between properties and their instances in the sciences. In response, I clarify some important background issues about property instances and their relations to properties which show why P&S's main argument fails. In addition, I provide a second reason to doubt their argument by highlighting reasons to think that instances, as well as properties, are plausibly sometimes multiply realized in the sciences